A solar cell module is known in which a reflective member which reflects at least some of incident light are placed on a back surface side of a solar cell (for example, refer to Patent Literature 1). In such a solar cell module, incident light which passes through a portion where the solar cell is not provided to the back side can be reflected to the side of the cell, thus improving the usage efficiency of the incident light. In the solar cell module of the related art, a plurality of strings of solar cells are placed in an aligned manner with a constant spacing, to form a group of strings.